Field of the Invention
This specification relates to wireless communication and, most particularly, to a method for transmitting data using a plurality of subbands and an apparatus using the same in a wireless LAN (wireless local area network, WLAN).
Related Art
The Wi-Fi is a Wireless Local Area Network (WLAN) technology that enables a device to be connected to the Internet in a frequency band of 2.4 GHz, 5 GHz or 60 GHz. A WLAN is based on Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard.
The IEEE 802.11n standard supports multiple antennas and provides a maximum data rate of 600 Mbits/s. A system that supports the IEEE 802.11n standard is called a High Throughput (HT) system.
The IEEE 802.11ac standard mostly operates in a 5 GHz band and provides a data rate of 1 Gbit/s or more. IEEE 802.11ac supports downlink Multi-User Multiple Input Multiple Output (MU-MIMO). A system that supports IEEE 802.11ac is called a Very High Throughput (VHT) system.
A IEEE 802.11ax is being developed as a next-generation WLAN for handling a higher data rate and a higher user load. The scope of IEEE 802.11ax may include 1) the improvements of the 802.11 physical (PHY) layer and the Medium Access Control (MAC) layer, 2) the improvements of spectrum efficiency and area throughput, 3) performance improvement in an environment under an interference source, a crowded heterogeneous network environment, and an environment having heavy user load.
The conventional IEEE 802.11 standard supports only Orthogonal Frequency Division Multiplexing (OFDM). In contrast, in a next-generation WLAN, supporting Orthogonal Frequency Division Multiple Access (OFDMA) capable of multi-user access is being taken into consideration.